PHP code with regexp for dutch phone are not working - php

Question

I actually used the expression from the solution given in Regular expression for Dutch phone number for my php code below, but this code is not working.
The code is simple but I don't see where I go wrong ?
define("REGEXP_PHONE_NL","(^\+[0-9]{2}|^\+[0-9]{2}\(0\)|^\(\+[0-9]{2}\)\(0\)|^00[0-9]{2}|^0)([0-9]{9}$|[0-9\-\s]{10}$)");
$string = "[phone]"; //based on solution given in https://stackoverflow.com/questions/17949757/regular-expression-for-dutch-phone-number
echo(filter_var($string, FILTER_VALIDATE_REGEXP,array("options"=>array("regexp"=>REGEXP_PHONE_NL))));

Answer 1

Regex itself works, but you forgot to put same characters in the beginning and in the end of the pattern (delimeters).
<?php
define("REGEXP_PHONE_NL","/(^\+[0-9]{2}|^\+[0-9]{2}\(0\)|^\(\+[0-9]{2}\)\(0\)|^00[0-9]{2}|^0)([0-9]{9}$|[0-9\-\s]{10}$)/");
$string = "[phone]"; //based on solution given in http://stackoverflow.com/questions/17949757/regular-expression-for-dutch-phone-number
var_dump(filter_var($string, FILTER_VALIDATE_REGEXP,array("options"=>array("regexp"=>REGEXP_PHONE_NL))));
See it working here.

Answer 2

You are missing to put regexp identifier character forward slash (/) in your regular expression pattern i add forward slash before and after,
Check this Demo code Viper
PHP
<?php
define("REGEXP_PHONE_NL","/(^\+[0-9]{2}|^\+[0-9]{2}\(0\)|^\(\+[0-9]{2}\)\(0\)|^00[0-9]{2}|^0)([0-9]{9}$|[0-9\-\s]{10}$)/");
$string = "[phone]"; //based on solution given in http://stackoverflow.com/questions/17949757/regular-expression-for-dutch-phone-number
echo filter_var($string, FILTER_VALIDATE_REGEXP,array("options"=>array("regexp"=>REGEXP_PHONE_NL)));
?>
Result
[phone]